<?php
$con=mysqli_connect("localhost","user","pass","db");
// Check connection
if (mysqli_connect_errno()){
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// Perform queries
$result = mysqli_query($con,"SELECT COUNT(*)\n"
. "FROM INFORMATION_SCHEMA.COLUMNS\n"
. "WHERE table_name = \'CustomersTable\'");
$something = mysqli_fetch_assoc($result);
echo $something;
mysqli_close($con);
?>
我希望代码能够回显某些内容的值,即表中的列数。但我没有看到任何印刷品。我做错了什么?
答案 0 :(得分:1)
您的查询错误。如下所示: -
<?php
$con=mysqli_connect("localhost","user","pass","db");
if (mysqli_connect_errno()){
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT COUNT(*) as total_count FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'CustomersTable'") or die(mysqli_error($con));
$something = mysqli_fetch_assoc($result);
echo $something['total_count'];//or do var_dump($something);
mysqli_close($con);
?>